Arrangement for starting alternating-current motors.



No. 629,897. Patented Aug. I899.

E. FERRARIS &. R. ARNO.

ARRANGEMENT FOR STARTING ALTERNATING CURRENT MOTORS. A umion filed Jul6, 1896.) (No Model.)

mt "bums PETERS no. PHOTKLLH'HQ, WASHINGTON. o. c

UNITED STATES PATENT OFFICE.

GALILEO FERRARIS AND RICCARDO ARNO, OF TUBIN, ITALY.

ARRANGEMENT FOR STARTING ALTERNATING-CURRENT MOTORS.

SPECIFICATION forming part of Letters Patent No. 629,897, dated August1, 1899. Application filed July '6, 1895. Serial No. 555,106. on model.)

T0 at whom it may concern:

Be it known that we, GALILEO FERRARIS, civil engineer and professor ofelectric technology, and RICOARDO ARNO, electrical engineer, residing atTurin, Italy, have invented certain new and useful Improvements inMethods of and Apparatus for Starting and Operating Alternating-CurrentElectric M0- tors; and we do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame, reference being had to the accompanyin g drawing, and to lettersof reference marked thereon, which forms a part of this specification.

Our invention relates to improvements in systems of electricaldistribution, and particularly relates to systems in which single phasecurrents are supplied to one or more circuits containing translatingdevices of the single-phase type, such as lamps, and at certain pointsof the system out-of-phase currents are produced to be used in startingalternating-current motors which are run at normal speed as single-phasemotors.

Referring to the drawing the figure is a view of the system in diagram,showing the motors connected to the single-phase mains, which alsosupply groups of lamps or other translating devices, here shown asarranged in multiple, together with the circuit carrying theout-of-phase currents or electromotive forces,with the devices andswitches by which the various connections are made and the desiredindications given.

Referring to the drawing, R S are the single-phase mains, supplied froma source of single-phase currents.

L L L are groups of incandescent lamps or other devices connected inparallel to the mains R S, the lamps being in parallel with each other.I

X Y Z represent the conductor, which receives energy from a phasedisplacing transform er. M.

M M M are motors which are connected while in operation with the linewires or conductors R S. These motors at normal speed are operated assingle-phase motors, being disconnected from the circuit X Y Z, carryingthe out-of-phase current or electromotive force, when normal speed isreached.

Furthermore, a characteristic feature of this invention is anarrangement which permits in a simple and practical manner the startingof any number of electromotors without a generator being required forproducing a current or supplementary conductor X Y Z being required fortransmitting a current of greater intensity than that which is necessaryfor the starting of one single motor. This result is-obtained asfollows:

In each receiving-station a switch 0 is arranged which serves to put theportion Y of the supplementary conductor X Y Z, which starts from thephase-displacing transformer M, which produces the current changed inits phase, into communication either with the motor intended to bestarted or with the portion Z of the supplementary conductor which goesto the successive receiving-stations in such a way that a subscriber isnot enabled to start his own motor without interrupting thecommunication of the successive motors with the generator M of thephase-displaced current. By this arrangement a subscriber can alwaysascertain whether atany moment he can make use of the supplementaryconductor X Y Z. In our system one phase-displacing transformer alonecan serve for starting a number of monophased asynchronous motors, evenwhen one of these is placed at a great distance, and thephase-displacing transformer produces and its secondary circuittransmits no larger current than that which is necessary to start thelargest of the motors.

The two-way switch 0, placed at each receiving-station, serves toconnect the part Y of the wire X Y Z coming from the phase-displacingtransformer either with the motor it is desired to start or with thebranch Z which leads to the following receiving-stations, so that areceiving-station cannot start its own motor without breaking theconnection between the following motors and the phase-displacingtransformer. It is thus a feature of our system that only one motor at atime can use the third wire, and in order that no attempt to start twomotors at once will be made it is necessary to provide some arrangementwhich will show when the third wire is in use at any point whatever. Itwill be noticed that when the third wire is not in use it is at adiiferent potential from that of the mains R S, but carries no current.\Vhen it is in use at a point beyond the station at which it is desiredto start the motor, a difference of potential will exist and a currentwill also be passing. Vhen it is in use at a point between the stationin question and the phase-changer M, the third wire will be entirelydead, as is obvious from the connection of the switch 0. There will beneither difference of potential nor current when the wire X Y Z is usedfor starting one of the preceding motors; but when it is used for thestarting of a subsequent motor there will be difference of potential andcurrent. It will therefore be sutlicieut that the receiving-station havea eurrent-indicator inserted upon the wire Y and a potential-indicatorbetween the wires Y and S. It can use the third wire when thecurrent-indicator reads Zero and the potential-indicator gives anyreading whatever other than zero, but not when both potential-indicatorand eurrent-indicator give readings nor when they are both at zero. Thedesired result can be attained in an easier and more practical manner bymeans of an arrangement by which when a current passes through the wireXYZ the effect of that current will be to break the circuit of thepotential-indicator. In such case every time the wire X Y Z is occupiedthe potential-indicator will mark zero, while when the wire X Y Z isfree it will indicate a difference of potential, so that it will benecessary only to observe these indications at the receiving-station.For this purpose it will be sufficient to replace the current-indicatoreither by an electromagnet A, as shown, as an instance, in the figure,or by some other apparatus which when put in motion by the cur-.

rent of the wire Y operates a circuit-breaker 22, inserted in thecircuit 1) q of the potentialindicator. A good substitute for thepotential-indicat-or is an apparatus placed in shunt between the wires Sand Y, which directly or indirectly indicate by a visible or some othernoticeable sign the existence of the tension. This apparatus can, forinstance, consist of an electromagnet V. In such case the visible orotherwise noticeable sign can be produced by the motions of itsarmature. Among the visible signs that can be produced there is one thatis very suitable, and consists in the lighting or extinguishing of anelectric lamp.

One manner of producing this effect is shown. The electric lamp Z isinserted between the main conducting-wires R S by means of the wires rand s. A circuit-breaker it, operated by the armature .2 of theeleetromagnet V, is situated between the wires. As long as the tensionexists the armature .2 will be raised and the lamp Z extinguished. Assoon as the tension ceases to exist the armature drops and the lamp willbe lighted.

The system works as follows: \Vhen the wire X Y Z is not used by any ofthe'receiving-stations, no current passes the electromagnets A, whichserve as current-indicator, and the circuit p q of the volt-indicatiugelectromagnet V is closed. This eleetromagnet will attract its armature.2 and break in \V the current of the lamp, which will thereby becomeextinguished. If, on the contrary, the wire X Y Z is used for startingthe motorM, the lamps will be lighted in all precedingreceiving-stations, for with the motor M, for instance, located betweenthe phase-displacing transformer and the motor M a current will passthrough the eleetromagnet A and will attract its armature, and thecircuitbreaker u will break the circuit 1) q of the volt-indicatingelectromognet V, and the circuit-breaker 10 remains closed and the lampslighted. As to the motors which follow the motor M no diilerence ofpotential will exist between the wires Q and Y, and thus thevolt-indicating electromagnet V will not attract its armature Thereforethe circuitbrcaker in will remain closed and the lamp Z lighted. Themotors which are beyond the motor M will receive no current from theout-of-phase line X Y Z, since there is no connection between the sourceof out-of-phase currentsand the line X Y Z beyondM. Hence thevolt-indicating eleetromagnet V at each station beyond M will notattract its armature z, and the circuit-breaker to will remain closedand each of the lamps at these stations will remain lighted. From thisit will be evident that when the lamps are lighted at any of thestations it will indicate that some (one or more) of the precedingstat-ions are at that time utilizing the out-of-phase energy to startthe motors.

It is easy to think of other arrangements by which the motions of thearmature w of the volt-indicating electromagnet V instead of serving toclose or break the circuit of a lampZ serve, on the contrary, to operatea mechanical device which will serve the same purpose.

Though we have illustrated our device in connection with motors, it isevident that it is equally applicable to any translating devicewhatever-as, for instance, a rotary transformerand though we have shownthe secondary member of the transformer M rota-ting and of the inductiontype it is evident that any mere reversal or substitution of any otherform of secondary will nevertheless give a system which is within thescope of our invention, though the forms which we have shown are thepreferred ones.

\Ve claim- 1. Ina system of electrical transmission and distribution,the combination of a source of single-phase alternating currents, aline-circuit, or circuits, extending therefrom, means located at apoint, or points, by which cutof-phase electromotive forces, orcurrents, are produced from the single-phase current, elcctrodynamicreceivers connected to the single-phase mains and capable of beingconnected with the conductor leading from the producer of out-of-phaseelectromotive force, or currents, and switching devices one for eachreceiver normally included in and forming part of the conductor leadingfrom the producer of out-of-phase electromotive force and so arrangedthat 011 manipulating any one of the said switching devices the circuitof the said out-of-phase conductor will be broken, and the correspondingreceiver will be connected to the producer of outbfphase electromotiveforce.

2. In asystem of electrical transmission and distribution, thecombination of a source of single-phase alternating currents, a circuitor circuits extending therefrom, means located at a point or points bywhich out-of phase electromotive forces, or currents, are produced fromthe single-phase current, electrodynamic receivers connected to saidsingle-phase mains, a circuit connected to the producer of out-of-phaseelectromotive forces or currents, extending between the variousreceivers, and means whereby the various receivers can only bedissimultaneously connected with the source of out-of-phaseelectromotive force.

3. In a system of electrical transmission and distribution, thecombination of a source of single-phase alternating currents, a circuitor circuits extending therefrom, means located at a point or points bywhich out-ofphase electromotive forces, or currents, are produced fromthe single-phase current, electrodynamic receivers connected to saidsinglephase mains, a circuit connected to the producer of out-of-phaseelectromotive forces or currents extending between the variousreceivers, a switch located near each of the re ccivers in the saidout-of-phase circuit by which its receiver can be connected to saidsource of out-of-phase electromotive force only when the other receiversat the same time are disconnected from the source of out-ofphaseelectromotive force.

4. In a system of electrical transmission and distribution, thecombination of a source of single-phase alternating currents, a circuitor circuits extending therefrom, means located at a point or points bywhich out-ofphase electromotive forces or currents are produced from thesingle-phase current, electrodynamic receivers connected to saidsingle-phase mains, a circuit connected to the producer of out-of-phaseelectromotive forces or currents extending between the variousreceivers, switches for connecting each receiver with the single-phasemains, other switches for connecting each receiver with the source ofout-of-phase electromotive force only when all the other receivers aredisconnected from the source of out-of-phase electromotive force, and anindicating device which is caused to give a signal when the receiver atany point is connected in the circuit carrying the outof-phase currentor electromotive forces.

5. In a system of electrical transmission and distribution, thecombination of a source of single-phase alternating currents, a circuitor circuits extending therefrom, means located at'a point or points bywhich out-ofphase electromotive forces or currents are produced from thesin gle-phase current, electrodynamic motors connected to saidsinglephase mains, a circuit connected to the producer of out-of-phaseelectromotive forces or currents extending between the various motors, aswitch for each motor for connecting it to the single-phase mains, aswitch for each motor which operates to connect its motor with thesource of out-of-phase electromotive force only when all of thepreceding switches are so positioned that the corresponding motors aredisconnected from both the source of out-of-phase electromotive forceand the circuit connected to said source and means near eachelectrodynamic motor operated by the motorbein g connected to theout-of-phase circuit so as to give a signal at its own point and at allpreceding points of the out-of-phase circuit where motors are located.

6. In a system of electrical transmission and distribution, thecombination of a source of single-phase alternating currents, a circuitor circuits extending therefrom, means located at a point or points bywhich out-ofphase electromotive forces or currents are produced from thesingle-phase current, electrodynamic motors connected to saidsinglephase mains, a circuit connected to the producer of out-of-phaseelectromotive forces or currents extending between the various motors, aswitch for each motor for connecting it to the single-phase mains, aswitch for each motor by which it can be connected with the outof-phasecircuit when all the other motors are disconnected from the source ofout-ofphase electromotive force, a magnet in the out-of-phase circuitfor each electrodynamic receiver operated by the motor being connectedto the source of out-of-phase electromotive force so as to give a signalat its own point and at all preceding points of the out-of-phasecircuit, where motors are located.

7. In a system of electrical transmission and distribution, thecombination of a source of single-phase alternating currents, a linecircuit, or circuits, extending therefrom, means located at a point, orpoints, by which out-ofphase electromotive forces, or currents, areproduced from the single-phase current, electrodynamic receiversconnected to the sin glephase mains and capable of being connected withthe conductor leading from the producer of out-of-phase electromotiveforce or currents, a magnet for each receiver located in series with theout-of-phase conductor, said magnet having an armature which controls asignaling device, and switching devices one for each receiver normallyincluded in and forming part of the conductor leading from the producerof out-of-phase electromotive force and so arranged that on manipulatingIIO any of the said switching devices the circuit of the saidout-of-phase conductor will be broken, and the corresponding receiverwill be connected to the producer of out-of-phase electromotive force.

8. In a system of electrical transmission and distribution, thecombination of a source of single-phase alternating currents, a linecircuit, or circuits, extending therefrom, means located at a point, orpoints, by which out-ofphase electromotive forces, or currents, areproduced from the single-phase current, electrodynamic receiversconnected to the singlephase mains and capable of being connected withthe conductor leading from the producer of out-of-phase electromotiveforce or currents, switching devices one for each receivernormallyincluded in and forming part of the conductor leading from theproducer of outof-phase electromotive force and so arranged that onmanipulating one of the said switching devices the circuit of the saidout-of-phase conductor will be broken, and the coi'respon ding receiverwill be connected to the producer of out-of-phase electromotive force, amagnet for each receiver located in series with the outof-phaseconductor, a magnet connected between the outof-phase mains and one ofthe sin gle-phase mains, whose circuit is controlled by the armature ofthe first-mentioned magnet, said second magnet having an armature whichcontrols the circuit of a single lamp connected in shunt across thebranch from the single phase mains which lead to the said motor. Intestimony that we claim the foregoing as our invention we have signedour names in presence of two subscribing witnesses.

GALILEO FERRARIS. RICCARDO ARNO. Witnesses:

GIVANI BATOSTA Boo'rn.

AL'BENO LOWORRA.

